Doc: Remove references to Qt 4 in Qt 5.0 in Qt Core documentation

Pick-to: 6.6
Change-Id: Ide0c1ed441c923753f1e81141460719161662c15
Reviewed-by: Jaishree Vyas <jaishree.vyas@qt.io>
Reviewed-by: Nicholas Bennett <nicholas.bennett@qt.io>
(cherry picked from commit a659dcf031e6c4ce112a9ec2e6d8f94f3ce96992)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/doc/src/containers.qdoc

@@ -351,7 +351,8 @@
      the problem exists for all the implicitly shared Qt containers.
 
     \section3 Java-Style Iterators
-    \l{java-style-iterators}{Java-Style iterators} were introduced in Qt 4. Their API is modelled
+    \l{java-style-iterators}{Java-Style iterators}
+    are modelled
     on Java's iterator classes.
     New code should prefer \l{STL-Style Iterators}.
 

src/corelib/doc/src/ipc.qdoc

@@ -390,7 +390,7 @@
     Qt's own build. For Windows systems, it was always the Windows backend. For
     Unix systems, it defaulted to the System V backend if the configuration
     script determined it was available. If it was not available, it fell back
-    to the POSIX one (since Qt 4.8). The POSIX backend could be explicitly
+    to the POSIX one. The POSIX backend could be explicitly
     selected using the \c{-feature-ipc_posix} option to the Qt configure
     script; if it was enabled, the \c{QT_POSIX_IPC} macro would be defined.
 

src/corelib/global/qnamespace.qdoc

@@ -617,7 +617,7 @@
            connection types, using a bitwise OR. When Qt::UniqueConnection is
            set, QObject::connect() will fail if the connection already exists
            (i.e. if the same signal is already connected to the same slot
-           for the same pair of objects). This flag was introduced in Qt 4.6.
+           for the same pair of objects).
 
     \value SingleShotConnection
            This is a flag that can be combined with any one of the above
@@ -2772,8 +2772,7 @@
     \value CheckStateRole       This role is used to obtain the checked state of
                                 an item. (Qt::CheckState)
     \value InitialSortOrderRole This role is used to obtain the initial sort order
-                                of a header view section. (Qt::SortOrder). This
-                                role was introduced in Qt 4.8.
+                                of a header view section. (Qt::SortOrder).
 
     Accessibility roles (with associated types):
 

src/corelib/kernel/qmetaobject.cpp

@@ -2276,10 +2276,9 @@ const char *QMetaMethod::typeName() const
     differently, and treat them according to the specific needs of your
     application.
 
-    \note Since Qt 5.0, \c moc expands preprocessor macros, so it is necessary
+    \note \c moc expands preprocessor macros, so it is necessary
     to surround the definition with \c #ifndef \c Q_MOC_RUN, as shown in the
-    example above. This was not required in Qt 4. The code as shown above works
-    with Qt 4 too.
+    example above.
 */
 const char *QMetaMethod::tag() const
 {

src/corelib/kernel/qobject.cpp

@@ -899,13 +899,13 @@ QMetaCallEvent* QMetaCallEvent::create_impl(QtPrivate::SlotObjUniquePtr slotObj,
 
     \section1 Dynamic Properties
 
-    From Qt 4.2, dynamic properties can be added to and removed from QObject
+    Dynamic properties can be added to and removed from QObject
     instances at run-time. Dynamic properties do not need to be declared at
     compile-time, yet they provide the same advantages as static properties
     and are manipulated using the same API - using property() to read them
     and setProperty() to write them.
 
-    From Qt 4.3, dynamic properties are supported by
+    Dynamic properties are supported by
     \l{Qt Designer's Widget Editing Mode#The Property Editor}{Qt Designer},
     and both standard Qt widgets and user-created forms can be given dynamic
     properties.
@@ -2402,7 +2402,7 @@ void QObject::removeEventFilter(QObject *obj)
     QCoreApplication::exec()), the object will be deleted once the
     event loop is started. If deleteLater() is called after the main event loop
     has stopped, the object will not be deleted.
-    Since Qt 4.8, if deleteLater() is called on an object that lives in a
+    If deleteLater() is called on an object that lives in a
     thread with no running event loop, the object will be destroyed when the
     thread finishes.
 
@@ -2443,8 +2443,7 @@ void QObject::deleteLater()
 
     If the same \a sourceText is used in different roles within the
     same context, an additional identifying string may be passed in
-    \a disambiguation (\nullptr by default). In Qt 4.4 and earlier, this was
-    the preferred way to pass comments to translators.
+    \a disambiguation (\nullptr by default).
 
     Example:
 

src/corelib/text/qstring.cpp

@@ -2054,16 +2054,15 @@ void qtWarnAboutInvalidRegularExpression(const QString &pattern, const char *whe
     \snippet qstring/stringbuilder.cpp 0
 
     There is nothing wrong with either of these string constructions,
-    but there are a few hidden inefficiencies. Beginning with Qt 4.6,
-    you can eliminate them.
+    but there are a few hidden inefficiencies:
 
     First, multiple uses of the \c{'+'} operator usually means
     multiple memory allocations. When concatenating \e{n} substrings,
     where \e{n > 2}, there can be as many as \e{n - 1} calls to the
     memory allocator.
 
-    In 4.6, an internal template class \c{QStringBuilder} has been
-    added along with a few helper functions. This class is marked
+    These allocations can be optimized by an internal class
+    \c{QStringBuilder}. This class is marked
     internal and does not appear in the documentation, because you
     aren't meant to instantiate it in your code. Its use will be
     automatic, as described below. The class is found in

src/corelib/thread/qthread.cpp

@@ -256,17 +256,16 @@ QThreadPrivate::~QThreadPrivate()
     documentation for terminate() and setTerminationEnabled() for
     detailed information.
 
-    From Qt 4.8 onwards, it is possible to deallocate objects that
-    live in a thread that has just ended, by connecting the
-    finished() signal to QObject::deleteLater().
+    You often want to deallocate objects that live in a thread when
+    a thread ends. To do this, connect the finished() signal to
+    QObject::deleteLater().
 
     Use wait() to block the calling thread, until the other thread
     has finished execution (or until a specified time has passed).
 
     QThread also provides static, platform independent sleep
     functions: sleep(), msleep(), and usleep() allow full second,
-    millisecond, and microsecond resolution respectively. These
-    functions were made public in Qt 5.0.
+    millisecond, and microsecond resolution respectively.
 
     \note wait() and the sleep() functions should be unnecessary in
     general, since Qt is an event-driven framework. Instead of

src/corelib/tools/qsharedpointer.cpp

@@ -139,8 +139,7 @@
     can also exceptionally be -1, indicating that there are no QSharedPointers
     attached to an object, which is tracked too. The only case where this is
     possible is that of QWeakPointers and QPointers tracking a QObject. Note
-    that QWeakPointers tracking a QObject is a deprecated feature as of Qt 5.0,
-    kept only for compatibility with Qt 4.x.
+    that QWeakPointers tracking a QObject is deprecated.
 
     The weak reference count controls the lifetime of the d-pointer itself.
     It can be thought of as an internal/intrusive reference count for